This invention relates generally to a fastening system and more particularly to an automatically adjustable fastening system for use in fastening deck boards to stringers in a pallet-making machine or the like.
Fabricated transportation and storage pallets may be constructed by fastening a plurality of deck boards to the top and bottom of a plurality of stringers. These stringers may be of the type generally known as solid stringers or of the type generally known as fabricated or block stringers and heretofore the completed pallet has been generally assembled and fastened entirely with manual labor using only pneumatic fastening devices, such as staple guns or nailing guns to complete the pallet.
Known prior art techniques have provided for the rapid fastening of the components of the pallet but did not provide means for automatically supplying and positioning the article components prior to the fastening station which is essential if the completed articles are to be efficiently assembled. In order to overcome the problems inherent in the prior art assembling machines, there was provided by the applicant's U.S. Pat. No. 3,755,871, issued Sept. 4, 1973, a new and unique pallet assembling machine which could be used to automatically construct a partial pallet of either the fabricated block-type or of the stringer-type. When the machine of the cited patent was combined with a similar machine, the two units could be used to automatically assemble the completed pallet.
The applicant's unique pallet assembling machine typified in the U.S. Pat. No. 3,755,871, comprised basically an automatic bulk stringer supply and feeder used in combination with an automatic deck board supply and unscrambler which was located above the stringer supply. These two supply members were interconnected in such a manner that the components could be accurately positioned together for manual and for automatic nailing or stapling to thereby provide a partial pallet which when turned over was introduced into a similar second pallet assembler to form the completed pallet.
When the subject pallet machine was completed it was found that manual fastening of the deck boards to the stringers was not entirely satisfactory since labor was expensive and the use of manual labor did not always result in a uniformly formed pallet. Attempts to automate the fastening portion of the automatic pallet machine required the use of new and novel fastening techniques inasmuch as the applicant's automatic pallet machine was a continuous machine as opposed to the prior art intermittent machine wherein a plurality of automatic fasteners could be moved into position as the pallet passed through the assembling station and was intermittently stopped beneath the fasteners.
The use of fixed staplers or nail guns could not be relied upon in a continuous system since the act of stapling or nailing could tend to disorient the position of the unfastened deck boards that had been placed on the stringers prior to being fastened. That is to say the shock of fixed stapling or nailing could move the oncoming unfastened deck boards out of their predetermined position resulting in a poor appearing and structurally unsound pallet.
Prior art fixed fastening stations or devices are typified by the following United States Patents which show various fastening methods wherein either the staple or nail gun is held in a fixed position or else is movable into position on the product or the product is movable to a fixed staple or nail gun:
______________________________________ Patent Number Inventor Issue Data ______________________________________ No. 3,774,833 Deshich November 27, 1973 No. 3,557,439 Dykeman January 26, 1971 No. 913,958 Inwood March 2, 1909 No. 1,949,108 Paxton February 27, 1934 No. 1,959,839 Paxton May 22, 1934 No. 2,884,637 Wandel May 5, 1959 No. 3,261,527 Sterner July 19, 1966 No. 3,591,067 Vial July 6, 1971 No. 3,717,924 Kennedy February 27, 1973 ______________________________________